Automatic relief-valve.



No. 802,113. PATENTED 001117, 1905. L. A. RABOURN.

AUTOMATIC RELIEF VALVE.

APPLIGATION FILED MAR.27. 1905.

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ATTORNEYS UNITED STATES PATENT OFFICE.

LAURENCE A. RABOURN, OF COLUMBUS, OHIO, ASSIGNOR OF ONE-HALF TO GEORGE K. ELLIOTT'AND EPHRAIM L. HARRIS, OF COLUMBUS,

OHIO.

. Specification of Letters Patent.

Patented Oct. 17, 1905.

Application filed March 27, 1905. Serial No. 252,153.

To all whom it may concern.-

.Be it known that I, LAURENCE A, RA- BOURN, a citizen of the United States, residing at Columbus, in the county of Franklin and State of Ohio, have invented certain new and useful Improvements in Automatic Relief-Valves, of which the following is a specification.

My invention relates to a new and useful improvement in automatic relief-valves, and more especially to automatic relief-valves for locomotive steam-chests.

The object of the invention is to provide a valve of the character described to be attached to the head or end of the steam-chest to automaitically establish communication between the atmosphere and the interior of the steam-chest when the steam is cut off therefrom, so as to prevent the piston from drawing in cinders, soot, &c., through the exhaust, thereby preventing injury to the piston-head and cylinder, which would occur should foreign matter be drawn in through the exhaust.

Another feature resides in the elimination from the valve of a piston-rod and the necessary packing therefor, it having been found by actual experience that the pistonrod or stem of the valve often breaks or is bent, causing the valve to become inoperative and making it necessary for the engineer to jam the valve or fasten it against movement, thus placing the device out of use.

Finally, the object of the invention is to provide a device of the character described that will be strong, durable, efficient, and simple and comparatively inexpensive to make and one in which the several parts will not be liable to get out of working order.

With the above and other objects in view the invention consists of the novel details of construction and operation, a preferable embodiment of which is described in the specification and illustrated in the accompanying drawings, wherein Figure 1 is a vertical sectional view of the valve and a portion of the steam-chest head or end. Fig. 2 is an under side view of the valve, and Fig. 3 is a horizontal sectional View taken on the line at a: of Fig 1 and showing the valve-nipple in plan.

In the drawings the numeral 1 represents the valve-casing, which is preferably cylindrical in form and placed in a vertical position. A threaded nipple 2, communicating with the interior of the casing, is screwed into a threaded opening 3 of the steam chest head or end 4. A short distance from its lower end the casing is formed with an interior annular valve-seat 5, having an upper inclined face adapted to receive the inclined end of the valve 6, hereinafter described. Immediately below the valveseat 5 the easing is formed with a ring of openings 7, and in its bottom I preferably provide a plurality of radial openings 8 and a central opening 9. By this provision of openings it will be apparent that air may be freely drawn into the valve-casing when the valve 6 is raised.

The valve is formed in its upper surface with a grooved annular recess or depression 10, adapted to receive and confine the lower end of a short coiled spring 11, the upper or free end of which terminates opposite or slightly above the longitudinal center of the nipple 2. At its upper end the valve-casing is formed with a screw threaded ring 12, adapted to receive an interiorly threaded cap 13, formed on its upper end with a boss 14, with which a wrench may be engaged to remove or place the cap in position. The cap is formed on its under side with a downwardlyextending stop 15, arranged cen-..

trally of the cap and the valve-casing and being of such size and proportion as to readily fit within the coiled spring when the valve is raised. The stop 15 projects downwardly into the cylinder some distance, so as to have its lower end below a slotted opening 16, formed in the valve-casing. The valve-casing is formed with a longitudinal enlargement 17, extending from about the opening 16 downwardly to the nipple, and a longitudinal passage 18 extends from the opening 16 to the interior of the nipple to establish communication between the upper end of the valve-casing and the nipple.

In utilizing my invention when the steam is cut off and the piston in the cylinder still working as, for instance, when the locomotive is coastingthe vacuum created by the working of the piston will raise the valve 6 and cause air to be drawn in through the openin s 7, 8, and 9 with such force as to raise the va ve 6 in the casing above the nipple until the spring 11 contacts with the under side of the cap and the valve itself abuts the stop 15. The spring, however, will cushion the valve and prevent the same from striking the stopboss 15 with sufficient force to injure it. On its upward movement after the upper end of the valve passes beyond the nipple the suction created by way of the passage 18 and opening 16 will continue to raise the valve and maintain it in its raised position. When steam is again turned into the steam-chest, a sufficient amount will pass up through the passage 18 and out of the opening 16 into the casing and over the valve to force the valve 6 downward. In. this downward movement the steam is assisted by the spring 11, which it is understood is compressed when the valve is moved upward and the vacuum being broken when the steam is admitted the spring will naturally expand or extend and start the valve on its downward or return movement. After the upper end of the valve passes below the upper portion of the bore of the nipple it will be subjected not only to the steam entering the valve-casing through the opening 16, but the steam passing along the upper portion of the said bore, and this pressure will be greater than the 7 pressure encountered at the lower portion of the bore of the nipple, thereby preventing dancing or balancing of the valve.

Having now fully described my invention, what I claim, and desire to secure by Letters Patent, is

1. In an automatic relief-valve, a casing provided with air-openings at its lower end and formed with an internal valve-seat, a stemless valve normally resting on the seat so as to close the casing against the admission of air, and resilient means supported on the valve at one end thereof.

2,. In an automatic relief-valve, a casing formed intermediate its ends with a nipple and having communication therewith, the said casing also being provided at its lower end with air-admitting openings and an internal valve-seat disposed above the openings, and a stemless valve normally resting on the seat andbelow the interior of the nipple, the said casing also having provision forthe establishment of communication between its upper portion and the interior of the nipple.

3; In an automatic relief-valve, a casing formedv at its lower end with air-admitting openings and at its upper end with a passage having communication with its bore, a nipple formed on the valve-casing and adapted to establish communication between a steamchest and the interior of the casing and between the steam-chest and the passage.

4. In an automatic relief-valve, a valvecasing provided at its lower end with air-admitting openings and a valveseat, provision for establishing communication between the valve-seat and a steam-chest, a stemless valve arranged within the casing and normally held upon the valve-seat by steampressure, and a stop carried by the casing at its upper end to limit the upward movement of the valve.

In testimony whereof I affix my signature in presence of two witnesses.

LAURENCE A. RABOURN.

Witnesses:

A. L. PHELPS, M. B. SoHLEY. 

